Study of Charge Diffusion in a Silicon Detector Using an Energy Sensitive Pixel Readout Chip

• Published in: IEEE transactions on nuclear science Vol. 62; no. 5; pp. 2349 - 2359
• Main Authors: Schioppa, E. J., Idarraga, J., van Beuzekom, M., Visser, J., Koffeman, E., Heijne, E., Engel, K. J., Uher, J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Atmospheric measurements; Charge measurement; Charge sharing; Detectors; diffusion; Energy measurement; Particle measurements; semiconductor detectors; Semiconductor device measurement; Silicon; timepix; x-ray imaging
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2015.2475124

A 300 μm thick thin p-on-n silicon sensor was connected to an energy sensitive pixel readout ASIC and exposed to a beam of highly energetic charged particles. By exploiting the spectral information and the fine segmentation of the detector, we were able to measure the evolution of the transverse profile of the charge carriers cloud in the sensor as a function of the drift distance from the point of generation. The result does not rely on model assumptions or electric field calculations. The data are also used to validate numerical simulations and to predict the detector spectral response to an X-ray fluorescence spectrum for applications in X-ray imaging.